Problem: Solve for $y$ : $12 = 1 + y$
Solution: Subtract $1$ from both sides: $ \begin{eqnarray} \\ \hphantom{12 {- 1}} &\hphantom{=}& \hphantom{y} \\ 12 &=& 1 + y \\ \\ {-1} && {-1} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ 12 {- 1} &=& y \\ \end{eqnarray} $ Simplify. $ y = 11$